Anti-drip calking gun and cartridge



3, 1957 H. B. COLLINS ANTI-DRP CALKING GUN AND CARTRIDGE 2 Sheets-Sheet1 Filed July 18, 1955 3, 1957 H. B. coLLlNs 2,815,151

NTI-DRIP CALKING GUN AND CARTRIDGE Filed July 18, 1955 z sheets-sheet 21N V EN TOR.

United States Patent() ANTI-DRIP CALKING GUN AND CARTRIDGE Harold B.Collins, Breedsville, Mich.

Application July 18, 1955, Serial No. 522,601

21 Claims. (Cl. 222-327) This invention relates to anti-drip calking gunand cartridge. The principal objects of this invention are:

First, to provide a calking glun having provision for releasing thefeeding pressure of the gun and a cartridge for the gun adapted topermit expansion of the calking material to prevent material fromdripping from the nozzle.

Second, to provide a calking gun with a ratchet plunger and a leveroperated plunger advancing dog and a locating dog wherein both dogs arearranged to be released from the shaft upon full extension of the leverto release the feeding pressure on the shaft.

Third, to provide a cartridge for a calking gun having a materialfeeding piston that is retractable under back pressure of the materialin the cartridge having a backing member for limiting retracting motionof the piston.

Fourth, to provide a calking gun and cartridge therefor with means forreleasing the pressure on the calking gun feed member and a two piecepiston and follower in the cartridge that are advanced successively bythe gun feed member so that the piston can retract a short distance tothe follower each time the pressure on the feed member is released.

Fifth, to provide a cartridge of calking material having a piston thatis automatically retractable when pressure on the piston is released.

Other objects and advantages will be apparent from a consideration ofthe following description and claims. The drawings, of which there aretwo sheets, illustrate several modifications of the cartridge and apreferred form of the calking gun in which the cartridges are adapted tobe used.

Fig. l is a fragmentary side elevational view partially in axial crosssection of a preferredform of the calking material cartridge.

Fig. 2 is a fragmentary enlarged cross sectional View of the rear end ofthe cartridge mounted in a calking gun in unactuated non-feedingposition.

; Fig. 3 is a fragmentary enlarged cross sectional view similar to Fig.2 and illustrating the gun and cartridge in actuated material feedingposition.

' Fig. 4 is an end elevational View of the head of the calking gun shaftthat coacts with the piston and follower of the cartridge.

- Fig 5 is a side elevational view partially in longitudinal crosssection of a calking gain with the first form of cartridge operativelymounted therein.

4 Fig. 6 is an enlarged fragmentary axial cross sectional view throughthe piston and follower of a modified cartridge and the modified head ofthe gun associated therewith.

Fig. .7 is a fragmentary elevational view partially in crosssectionillustrating the feed mechanism of the gun shown in Fig. 5 in actuatedfeeding position.

1 Fig. 8 is a fragmentary axial cross sectional -viev/ tlivcwith the4gun shown in Figs. 5 and 7.

` of a calking gun plunger shaft 11.

Calking guns and cartridges of calking material therefore are wellknown. Calking materials commonly used in the cartridges and guns aresemi-fluid plastic materials that are substantially compressible.Heretofore even when the pressure of the feeding mechanism of the gunwas released the pressure built up in the calking material continued toforce material out of the nozzle of the cartridge in undesirabledribbles that waste the calking material and create messy conditionsaround the work. Calking guns have been devised that will release thefeeding pressure of the gun on the cartridge but these guns haverequired manual disengagement of the rachet shaft of the gunindependently of operation of the calking gun lever and no provision hasbeen made for releasing the internal pressure that has been built upwithin the cartridge of calking material. i

In Fig. 1 there is illustrated a tubular cartridge of calking materialhaving a cylindrical body 1 with a nozzle 2 forming a discharge openingon its forward end. The calking material 3 is retained in the body by acircular piston plate or backing member 4 having a flexible sealingplate 5 secured to its forward face by means of staples or teeth 6struck forwardly from the piston plate Aand crimped through the sealingplate. The sealing plate and piston plate form a piston or a compressionmember adapted to transmit compressive force to the calking ma terial.In order to support the piston plates 4 and 5 in operative position thepiston plate 4 is backed up by a rigid cylindrical follower ring 7having an annular flange forming a front wall or inwardly extendingprojection 8 on its forward end. The rear end of the body 1 has aninwardly turned bead or rim 9 retaining the piston and follower ringwithin the body.

As appears more clearly in Figs. 2 and 3 the rear end of the body 1 andopening within the flange 8 of the follower ring are adapted to receiveand pass the head 10 When the cartridge is mounted in a calking gunhaving a supporting charnber wall or frame 12 and back wall 13 throughwhich the shaft 11 extends, advancing motion of the shaft and head willrst press the central portion of the piston plate 4 forwardly from theflange of the follower ring 7. The head 10 is provided with rearwardlyextending arms 14 with outwardly turned ears or projections 15 on theirrear ends that overlap and engage the flange 8 of the follower ring toadvance the follower ring past the piston plate by a distance equal tothe length of the arms 14.

The follower ring 7 is fitted tightly within the body 1 and may have asharp rear edge 16 that tends to dig into the surface of the body 1 toprevent rearward motion of the follower ring. In any case the followerring has suicient frictional engagement with the body 1 to resist theinternal pressure in the follower ring. When the shaft 11 and head 10are retracted by any means to the position indicated by the dotted lines10A in Fig. 3 the piston plate 4 and sealing plate 5 are free to retractthe short distance to the Harige 8 thus releasing internal pressure inthe calking material 3 and preventing drip from the spout 2.

Figs. 5 and 7 illustrate a highly practical gun for ef fecting releaseof the piston of a cartridgeof calking material. The gun includes aframe 17 with a handle 18 on the rear end thereof. The forwardlyextending body 12 of the frame is provided with a back wall 13 and afront wall 131 to form an elongated chamber for removably receiving thecartridge. A cross piece 19 on the rear of the frame coacts with theback wall 13 in providing spaced.

An operating lever 23 is pivotally mounted in the,

frame on the pivot 24 in gripping relation to the handle 18. A spring 25constantly biases the lever to forward extended position. The upper endof the lever 23 carries a pivot pin-260m which the shaft feeding dog 2'7is pivoted. A spring 28 constantly biases the dog 27 toward engagedposition with theteeth 22 but ears or shoulder. portions 29 on the dogare engageable with` theforward endl of the bearing 21 and constitutemeans to move the dog to disengaged position when the lever 23 is fullyextended. The spring 2S is stronger than the spring 23 so as to overcomethe latter and automatically effect disengagement of the dog. Pivotallysupported on the frame 17 ahead of the lever 23 is a locking dog 30supportedV on the pivot 31. A spring 32 constantly urges the locking.do'ginto locking engagement with the teeth 22 but coacting releaseportions 33 on the lever and the locking dog engage and constitute meansto move the locking dog out of engagement with the teeth when the lever23 is fully extended.

It will be seen that the operator of the gun and cartridge has only tofully release the operating lever 23 to release the shaft of the gun.Internal pressure built up in the calking material will then force thepiston plate, seal plate and head rearwardly until the piston plateengages the follower ring to prevent complete and unneccessaryretraction of the piston. This expansion of the calking materialprevents the material from dribbling from the nozzle.

Fig. 6 illustrates a modified form of cartridge that is cooperative withthe gun. In this cartridge the piston plate 34 is mounted within theshort cylindrical follower 35 rather than ahead of the follower as inFigs. 1 to 3. The piston plate has a sealing exible plate 36 secured toits forward face by the crimping nger 37 struck from the plate but thesealing plate coacts with the interior of the follower ring to preventrearward escape of the calking material. The piston plate 34 and sealingplate 36 act as a unit as a piston. The forward face 38 of the followerring has a central flanged opening 39 of substantial sizeformed thereinso that back pressure in the calking material acts through the followerring and against the forward face of the sealing plate when the head isretracted. The rea-r edge of the follower ring has lugs 40 stluckinwardlv forming projections to retain the piston plate within thefollower ring and to limit retracting motion of the piston'plate. As inthe first form of cartridge the follower ring 35 has a tight frictionalengagement within the body 1 to resist and prevent backward motion ofthe follower ring and the piston plate when the piston plate has beenretracted intoV engagement with the lugs 40.

Fig. 8 illustrates a. third modified form of cartridge which has theadvantage of being the least expensive to manufacture but which does notgive as full control of the material in the cartridge as the otherforms. In this cartridge the sealing plate or piston 41 is secureddirectly to the forward face of the cylindrical follower ring 42 as bythe teeth 43. The front face of the follower or backing ring thus takesthe place of the piston plate in the other forms of the cartridge. Inorder to allow for expansion of the calking material after the head 10is retracted the backing ring 42 is sized to have a frictional butmovable engagement within the body 1 under the influence of backpressures created within the calking material. Further the rear edge ofthe backing ring is rolled inwardly as at 44 to prevent the backing ringfrom digging into and locking against the inside of the body. Thus thefollower ring and its sealing plate are adapted to move rearwardly asfar as permitted by the retracting head and as far as required forexpansion of the calking material'.

Itis pointed out that the' same gun structure coacts with equal effectand utility with the several forms of the cartridge and plunger headdisclosed. In the fully extended orlunactuated position of the operatinglever of the gun both the driving dog and the locking dog are disengagedfrom the plunger shaft thus automatically disengaging and releasing theplunger shaft so that it can retract under the influence of compressiveforce built up in the calking compound.

In all forms of the cartridge disclosed the compressive force of theactuated plunger shaft and plunger head are maintained through thepiston to the calking compound to feed the compound from the end of thecartridge. Advancing motion of the plunger head also advances thebacking ring or member that supports and retains the. piston in thecartridge. In each form of the cartridge retracting motion of the pistonis permitted to accommodate expansion of the compressed calking materialand to retract the plunger shaft when the feeding operation is stopped.There is thus a lost motion relationship between the plunger shaft andthe calking material in the cartridge. The lost motion between theplunger shaft and the calking material is obtained by different means inthe several forms of the cartridge illustrated and the examplesillustrated in Figs. 2 and 6 limit expansion of the calking materialwhereas the example shown in Fig. 8 is not so limited.

Having thus described the invention, what is claimed as new and isdesired to be secured by Letters Patent is:

l. A calking gun and cartridge therefor comprising a frame forming achamber with a front wall and back wall, a handle on said frame, a crosspiece on said frame spaced from said back wall, a plunger shaftjournaled in said back wall and cross piece and having ratchet teethformed in its underside, an elongated tubular cartridge of calkingcompound positioned in said chamber and having a constantly open nozzleprojecting through said front wall, a cylindrical follower ring in therear end of said cartridge having frictionally holding engagement withthe wall of the cartridge and having a front wall with a anged openingof substantial size therein, a piston plate positioned within said ringand having a flexible sealing plate on its forward face in sealingengagement with the inside of the ring, inwardly turned projections onthe rear of said ring retaining said plates for limited axial movementin said ring, a head on said plunger shaft coacting with said pistonplate, a lever pivoted on said frame in gripping relation to said handleand spring biased to extended position, a first dog pivoted on saidlever and biased to driving engagement with said teeth on compressingmotion of the lever to advance said shaft, a shoulder portion on saidfirst dog engageable with the cross piece on said frame in the fullyextended position of the lever to disengage the dog from the shaft, asecond dog pivoted on said frame and biased to locking engagement withthe teeth on said shaft to prevent retraction of the shaft, and coactingrelease portions on said lever and said second dog engageable in thefully extended position of the lever to move the second dog to shaftreleasing position.-

2. A calking gun and cartridge therefor comprising a frame forming achamber with a front wall and back: wall, a handle on said frame, across piece on said frame` spaced from said back wall, a plunger shaftjournaled in said back wall and cross piece and having ratchet teethformed in its underside, an elongated tubular cartridge of of calkingcompound positioned in said chamber and having a constantly open nozzleprojecting through saidv front wall, a cylindrical follower ring in therear end of,

on the rear of said ring retaining said plates for limited axialmovement in said ring, a head on said plunger shaft" coacting with saidpiston plate, a lever pivotedon said frame in gripping relation to' saidhandle and springtv biased to extended position,l a rs't dog" pivoted onsaid" lever and biased to driving engagement with said teeth oncompressing motion of the lever to advance said shaft, a portion on saidfirst dog engageable with said framey in the fully extended position ofthe lever to disengage the dog from the shaft, a second dog pivoted onsaid frame and biased to locking engagement with the teeth on said shaftto prevent retraction of the shaft, and means to move the second dog toshaft releasing position.

3. A calking gun and cartridge therefor comprising a frame forming achamber with a front wall and back Wall, a handle on said frame, a crosspiece on said frame spaced from said back Wall, a plunger shaftjournaled in said back wall and cross piece and having ratchet teethformed in its side, an elongated tubular cartridge of calking compoundpositioned in said chamber and having a nozzle directed through saidfront wall, a cylindrical follower ring in the rear end of saidcartridge having frictionally holding engagement with the wall of thecartridge and having a front wall With an opening of substantial sizetherein, a piston positioned within said ring in sealing engagement withthe inside of the ring, inwardly turned projections on the rear of saidring retaining said piston for limited axial movement in said ring, ahead on said plunger shaft coacting with said piston, a lever pivoted onsaid frame in `gripping relation to said handle and spring biased toextended position, a tirst dog actuated by said lever and biased todriving engagement With said teeth on compressing motion of the lever toadvance said shaft, a portion on said first dog engageable with saidframe in the fully extended position of the lever to disengage the dogfrom the shaft, a second dog movable independently of said lever andbiased to locking engagement with the teeth on said shaft to preventretraction of the shaft, and means to move the second dog to shaftreleasing position.

4. A calking gun and cartridge therefor comprising a frame forming achamber with `a front Wall, a handle on said frame, a cross piece onsaid frame spaced from said wall, a plunger shaft journaled in saidcross piece and having ratchet teeth formed in its side, an elongatedtubular cartridge of calking compound positioned in said chamber andhaving a nozzle directed through said front wall, a cylindrical followerring in the rear end of said cartridge having frictionally holdingengagement with the wall of the cartridge and having a front wall withan opening of substantial size therein, a piston positioned Within saidring in sealing engagement with the inside of the ring, inwardly turnedprojections on the rear of said ring retaining said piston for limitedaxial movement in said ring, a head on said plunger shaft coacting withsaid piston, a lever pivoted on said frame in gripping relation to saidhandle and spring biased to extended position, a first dog actuated bysaid lever and biased to drivingengagement with said teeth oncompressing motion of the lever to advance said shaft, means actuated inthe fully extended position of the lever to disengage the dog from theshaft, a second dog movable independently of said lever and biased tolocking engagement with the teeth on said shaft to prevent retraction ofthe shaft, and means to move the second dog to shaft releasing position.

5. A calking cartridge comprising an elongated tubular body having aconstantly open nozzle at its front end, a cylindrical follower ring inthe rear end of said cartridge having frictionally holding engagementwith the wall of the cartridge and having a front wall with an openingof subtantial size therein, a piston plate positioned Within said ringand having a flexible sealing plate in sealing and sliding engagementwith the inside of the ring, inwardly turned projections on the rear ofsaid ring retaining said plates for limited axial movement in said ring,and a retaining rim on the back of said body retaining said ringtherein.

6. A calking cartridge comprising an elongated tubular body having anozzle at its front end, a cylindrical follower ring in the rear end ofsaid cartridge having frictionally holding engagement with the wall ofthe cartridge and having a front wall with an opening of substantialsize therein, a piston positioned within said ring in sealing andsliding engagement with the inside of the ring, and inwardly turnedportions on the rear of said ring retaining said piston for limitedaxial movement in said ring.

7. A calking gun and cartridge therefor comprising a frame forming achamber with a front wall and back wall, a handle on said frame, a crosspiece on said frame spaced from said back wall, a plunger shaftjournaled in said back wall and cross piece and having ratchet teethformed in its underside, an elongated tubular cartridge of calkingcompound having a cylindrical body positioned in said chamber and havinga constantly open nozzle projecting through said front wall, acylindrical follower ring in the rear end of said cartridge havingfrictionally holding engagement with the wall of the cartridge andhaving a front wall with an opening of substantial size therein, apiston plate positioned within said body ahead of said ring and having aflexible sealing plate on its forward face in sealing engagement withthe inside of the body, a head on said plunger shaft coacting with saidpiston plate through the opening in said ring, projections on said headspaced rearwardly from the face thereof to engage the front wall of saidring, a lever pivoted on said frame in gripping relation to said handleand spring biased to extended position, a rst dog pivoted on said leverand biased to driving engagement with said teeth on compressing motionof the lever to advance said shaft, a shoulder portion on sai-d firstdog engageable with the cross piece on said frame in the fully extendedposition of the lever to disengage the dog from the shaft, a second dogpivoted on said frame and biased to locking engagement with the teeth onsaid shaft to prevent retraction of the shaft, and coacting releaseportions on said lever and said second dog engageable in the fullyextended position of the lever to move the second dog to shaft releasingposition.

8. A calking gun and cartridge therefor comprising a frame forming achamber with a front wall, a handle on said frame, a cross piece on saidframe spaced from said wall, a plunger shaft journaled in said crosspiece and having ratchet teeth formed in its side, an elongated tubularcartridge of calking compound having a cylindrical body positioned insaid chamber and having a nozzle projecting through said front wall, acylindrical. follower ring in the rear end of said cartridge havingfrictionally holding engagement with the wall of the cartridge andhaving a front wall with an opening of substantial size therein, apiston positioned within said body ahead of .said ring in sealingengagement with the inside of the body, a head on said plunger shaftcoacting with said piston through the opening in said ring, projectionson said head spaced rearwardly from the face thereof to engage the frontwall of said ring, a lever pivoted on said frame in gripping relation tosaid handle and spring biased to extended position, a first dog actuatedby said lever and biased to driving engagement with said teeth oncompressing motion of the lever to advance said shaft, means actuated inthe fully extended position of the lever to disengage the dog from theshaft, a second dog movable independently of said lever and biased tolocking engagement with the teeth on said shaft to prevent retraction ofthe shaft, and means to move the second dog to Shaft releasing position.

9. A gun and cartridge for dispensing semi-fluid material comprising aframe forming a chamber with a front wall and back wall, a handle onsaid frame, a cross piece on said frame spaced from said back wall, aplunger shaft journaled in said back Wall and cross piece and havingratchet teeth formed in its side, an elongated tubular cartridge ofsemi-fluid material of plastic consistency havl ing a cylindrical bodypositioned in said chamber and having a nozzle directed through saidfront Wall, a piston positioned within said cartridge and having aexible sealing plate on its forward face in sealing relation with theinside of the cartridge, a head on said plunger shaft coacting with saidpiston, a lever pivoted on said frame in gripping relation to saidhandle and spring biased to extended position, a rst dog pivoted on saidlever and biased to driving engagement with said teeth on compressingmotion of the lever to advance said shaft, a shoulder portion on saidrst dog engageable with said frame in the fully extended position of thelever to disengage the dog from the shaft, a second dog carried by saidframe and biased to locking engagement with the teeth on said shaft toprevent retraction of the shaft, and coacting release portions on saidlever and said second dog engageable in the fully extended position ofthe lever to move the second dog to shaft releasing position.

l0. A gun and cartridge for dispensing semi-huid material comprising aframe forming a chamber with a front wall, a handle on said frame, across piece on said frame spaced from said wall, a plunger shaftjournaled in said cross piece and having ratchet teeth formed in itsside, an elongated tubular cartridge of semi-huid material of plasticconsistency having a cylindrical body positioned in said chamber andhaving a nozzle directed through said front wall, a piston positionedwithin said cartridge and in sealing relation with the inside of thecartridge, a head on said plunger shaft coacting with said piston, alever pivoted on said frame in gripping relation to said handle andspring biased to extended position, a first dog actuated by said leverand biased to driving engagement with said teeth on compressing motionof the lever to advance said shaft, means actuated in the fully extendedposition of the lever to disengage the dog from the shaft, a second dogcarried by said frame and biased to locking engagement with the teeth onsaid shaft to prevent retraction of the shaft, and coacting releaseportions on said lever and said second dog engageable in the fullyextended position of the lever to move the second dog to shaft releasingposition.

ll. ln a calking gun having a head adapted to be advanced in step bystep fashion by a ratchet dog, a locking dog connectable with said headto prevent retracting motion thereof, means Ifor moving said dogs out ofoperative connection with said head to permit retraction of the latter,a cartridge positioned ahead of said head, a piston plate having asealing plate on its forward surface positioned in sealing engagement inthe rear of said cartridge and engageable on its rear side with saidhead, and a follower ring in said cartridge having locking frictionalengagement therewith, said head being engageable with said piston platethrough said ring, coacting portions on said head and said ring capableof advancing said ring with said head, other coacting portions of saidplate and said ring limiting retracting motion -of said plate, said headbeing retractable away from said plate through said ring.

12. In a calking gun having an advanceable and retractable head, acartridge comprising. a tubular body with a piston plate having asealing plate on its forward surface positioned in sealing relation inthe rear of said body and engageable on its rear side with said head,and a follower ring in said cartridge having rearwardly lockingfrictional engagement therewith, said head being engageable with saidpiston plate through said ring, coacting portions on said head and saidring capable of advancing said ring with said head in rearwardly spacedrelation to said piston plate, other coating portions on said plate andsaid ring limiting retracting motion of said piston plate, said headbeing retractable away from said piston plate through said ring.

l`3. ln a calking gun having an advanceable andretractable head, acartridge comprising a cylindrical body witha nozzle on one end, apiston positioned in sealing relationlv in the rear of said cartridgeand engageable on its rear side with said head, and a following ring insaid cartridge having rearwardly locking frictional engage menttherewith, said head being engageable with said piston through saidring, overlapping portions of said head and said ring capable ofadvancing said ring with said head in rearwardly displaced relation tosaid piston, overlapping portions on said piston and said ring limitingretracting motion of said piston relative to said ring, said head beingretractable away from said piston through said ring.

14. A cartridge for semiuid material of plastic consistency comprising atubular body having a discharge nozzle on its front end, a pistonpositioned in the rear end of said body and having a exible sealingplate on its forward face, a cylindrical backing ring in said bodybehind said piston and having an annular flange on its forward end inbacking engagement with said piston, said piston being exposed to therear of the body within the opening in said annular flange, said ringhaving frictional rearwardly locking engagement with the interior ofsaid body, said ring and said piston being separately movable relativeto said body.

l5. A cartridge for semifluid material of plastic consistency comprisinga tubular body having a discharge nozzle on its front end, a pistonpositioned in the rear end of said body in sealing engagement with saidbody, a cylindrical backing ring in said body behind said piston andhaving a radially inwardly extending projection on its forward end inbacking engagement with said piston, said piston being exposed to therear of the body within the opening inwardly of said projection, saidring and said piston being separately movable relative to said body.

16. A cartridge for semiuid material of plastic consistency comprising atubular body having a discharge nozzle on its front end, a pistonpositioned in the rear end of said body, a cylindrical backing ring insaid body and having a radially inwardly extending projection on one endin backing engagement with said piston, said piston being exposed to therear of the body within the opening inwardly of said projection, saidring and said piston being separately movable relative to said body.

17. ln a calking gun having an advanceable and retractable head, acartridge comprising a cylindrical body with a nozzle on one end, apiston plate having a sealing plate on its forward surface positioned insealing relation in the rear of said cartridge and engageable on itsrear side with said head, and a follower ring in said cartridge havingrearwardly locking frictional engagement there* with, said head beingengageable with said piston plate through said ring, coacting portionsof said plate andsaid ring capable of advancing said ring with said headand with said ring extending rearwardly from said piston plate, othercoacting portions on said plate and said ring limiting retracting motionof said piston, said head being retractable away from said pistonthrough said ring.

l'8`. A cartridge of calking material comprising a cylindrical body witha discharge opening in its front end, a rigidy ring slidably mounted inthe rear vof said body and having rearwardly locking engagement with thebody, a radially inturned annular ange on said rin'g adapted to receivethrust force from a plunger head to advance said ring in said body, anda compression member closing the rear of said body and having itsperiphery in sealing engagement with said ring and being advanceablewith said ring, said compression member being engageable centrallythereof by the plunger head to apply compressive force to the calkingmaterial through the center of the ring and being movable relative tothe ring t-o accommodate expansion of the calking material uponretraction of the plunger.

19. A cartridge of calking material comprising a cylindrical body with adischarge opening in its front end, a rigid ring slidabl'y mounted inthe rear of said body, a radially intnrned annular flange on said ringadapted to receive thrust force from a plunger head to advance said ringin said body, and a compression member closing the rear of said body andhaving its periphery in sealing engagement with said ring and beingadvanceable with said ring, said compression member being engageablecentrally thereof by the plunger head to apply compressive force to thecallring material through the center of the ring and being movablerelative to the ring to accommodate expansion of the callting materialupon retraction or" the plunger.

20. Dispensing apparatus for semi-liquid compressible materialcomprising a gun removably receiving a tubular cartridge of thematerial, a plunger shaft on said gun having a head projectable into therear end of said cartridge, a lever pivoted in gripping relation on saidgun and biased to unactuated extended position, means on said gun toadvance and hold said shaft in all actuated retracted positions of saidlever, means on said gun to disengage said first means and permitretraction of said shaft in said cartridge in the extended position ofsaid lever, said cartridge having a tubular body open at the rear end toreceive said head and said shaft, and a piston slidable in said body andhaving its periphery in sealing relation thereto, said piston beingmovable rearwardly in said body under compressive force stored in saidmaterial when said head is disengaged from said first means, and havinga backing member adapted to receive advancing force from said head.

21. Dispensing apparatus for semi-liquid compressible materialcomprising a gun removably receiving a tubular cartridge of thematerial, said cartridge having a closure and material expelling memberin its rear end including a rigid annular holding ring in radiallysupported relation to the wall of the cartridge and an imperviouscentral element within said ring and movable relative to the ring intoexpelling contact with the material, a plunger shaft on said gun havinga head projectable into contact with said expelling member, said headhaving a central area of lesser diameter than said ring engageable withsaid central element within the outline of said ring, and rearwardlyodset radially projecting parts on said head engageable with said ringafter said central area has advanced said impervious central element.

References Cited in the file of this patent UNITED STATES PATENTS387,234 Hutchinson Aug. 7, 1888 850,583 Howard Apr. 16, 1907 1,270,835Iersemann July 2, 1918 1,318,928 Shields Oct. 14, 1919 2,115,591Sherbondy Apr. 26, 1938 2,233,587 Crewe Mar. 4, 1941 2,367,347 GoodyJan. 16, 1945 FOREIGN PATENTS 750,742 France Aug. 17, 1933

